Hybrid fabrics for extreme wear industrial and apparel applications

ABSTRACT

Twisted, non-blended hybrid yarns are provided that are suitable for the fabrication of abrasion resistant garments and other textile articles. One or more polyolefin fibers are ply twisted together with one or more non-polyolefin fibers in a manner that utilizes the properties of each fiber type. A plurality of the twisted, non-blended hybrid yarns is then woven or knitted into fabrics, such as twill woven denim, or formed into ropes, such as braided ropes.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of co-pending U.S. ProvisionalApplication Ser. No. 62/753,606, filed on Oct. 31, 2018, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND Technical Field

This technology relates to hybrid yarns and articles made from thehybrid yarns.

Description of the Related Art

High performance fibrous materials formed from high strength fibers arewell known in various industries. High tenacity fibers, such as SPECTRA®polyethylene fibers or aramid fibers such as KEVLAR® fibers, are wellknown as useful for the formation of high performance armor articlesbecause of their very high strength to weight performance, good wearresistance, cut resistance and slash resistance at low fiber volumes. Inrecent years, the use of such high performance fibers has been extendedto various non-armor industries, such as textile industries thatfabricate wearable textile articles such as sports apparel and footwear.

Traditionally, such wearable textile articles have been fabricated fromlow strength natural fibers, such as cotton or wool, or low strengthsynthetic fibers, such as polyester or elastomeric fibers such aspolyurethane (e.g., spandex) fibers. Such low strength fibers are verycomfortable and are easily colored to be given a fashionable appearance,but they are also known to have relatively poor durability and wearresistance. Therefore, fabrics formed from these low strength fibertypes are not ideal for use in apparel that will be subjected to extremewear conditions, such as protective clothing for motorcyclists,bicyclists, skateboarders, industrial workers, or the like. Onealternative material useful in fabricating extreme use protectivegarments is leather, which is known to have better wear resistance anddurability than similar articles formed the aforementioned low strengthfibers and is considered fashionable by many. However, leather articleshaving the desired level of durability and wear resistance must be quitethick, which makes the material very heavy and potentially uncomfortablefor the user, so they too are not ideal. This has led to the explorationof using high performance fibers such as polyethylene or aramid fibersin such non-traditional applications for such fiber types.

In one example, it has been known to incorporate high performancefabrics within existing clothing garments to provide added abrasionresistance to the entire article or to portions of the article. U.S.Pat. No. 9,003,563, for example, provides protective clothing wherein alayer of KEVLAR® aramid-based fabric or a polyethylene based fabric isprovided as an interior liner that is sewn onto selected interiorsurfaces of an existing garment.

In another example, it is known to fabricate textile articles havingimproved durability by weaving or knitting together yarns of differentmaterials. For example, U.S. Pat. No. 9,624,608 provides architecturallyreinforced denim fabrics for manufacturing athletic gear for athletesengaging in extreme sports, having moisture regulation properties andhigh abrasion resistance. The reinforced denim materials incorporateboth natural cotton fibers and high performance fibers such as KEVLAR®aramid fibers or polyethylene fibers as warp and/or fill (weft) threadsin the woven structure. The natural fibers and the high performancesynthetic fibers remain separate from each other but together form asingle fabric layer.

In yet another example, it has also been known to manufacture fabrics byweaving or knitting together a plurality of hybrid yarns, wherein theindividual hybrid yarns are formed by blending together more than onetype of fiber. For example, related U.S. pre-grant publications2002/0104576, 2002/0106956 and 2002/0111099 teach blending anon-performance fiber having properties such as good dyeability andsoftness with a high performance fiber having great strength to form anintimate blend yarn that mixes together different filament types informing a single fiber (a bundle of filaments). Similarly, U.S.pre-grant publication 2005/0208855 teaches forming blends combiningmodacrylic filaments, cotton staples and aramid filaments into singlefibers with are fabricated into textile articles having electrical arcand flame protection.

Each of these types of hybrid fabrics of the related art, except forU.S. pre-grant publication 2005/0208855, alleges to be abrasionresistant materials without providing supporting data. U.S. pre-grantpublication 2005/0208855 does provide data in the form of an industrystandard Taber Abrasion testing as per ASTM D3884 (Standard Guide forAbrasion Resistance of Textile Fabrics (Rotary Platform, Double-HeadMethod)). However, their abrasion resistance properties remaininsufficient for extreme protective clothing applications, such asmotorcyclists. The present disclosure provides a solution to this needby manufacturing fabrics from new hybrid yarns wherein high tenacitypolyolefin fibers are twisted together with non-polyolefin fibers,rather than being blended or formed into core-sheath fibers, wherein thepolyolefin fibers form greater than 20% of the total yarn surface areabut preferably less than 75%, and a plurality of the hybrid yarns arethen formed into garments such as by weaving or knitting. Thesignificant presence of the high tenacity polyolefin fiber at the yarnsurface provides the enhanced abrasion resistance without adding toomuch weight or cost to the material. The different fiber types are notblended together because polyolefin filaments positioned in the interiorof the blended yarn rather than at the surface do not aid in improvingabrasion resistance and therefore are wasteful and even deleterious tothe desired fabric properties where a balance of properties is needed,such as softness, low weight and dyeability, which are propertiesprovided by the non-polyolefin fiber types.

As further proven by the inventive examples, the present disclosureprovides improvements in abrasion resistance and durability not achievedby any other fabric of the related art, while also possessing desirableproperties such as good softness, low weight and dyeability that aredesirable in garment applications. Even in comparison to U.S.2005/020885, the materials of the present disclosure have a TaberAbrasion resistance of over 15 times greater, with the present materialseven being tested against an even coarser testing wheel than that ofU.S. pre-grant publication 2005/0208855 with a load of the same weight.Accordingly, the presently disclosed materials are especially attractiveand effective for use in protective clothing applications when a usercan be seriously hurt if the clothing they are wearing wears out andexposes skin to extreme conditions. This need for abrasion resistant,highly durable, dyeable and lightweight textile materials also extendsto many non-wearable textile applications, such as tents, canopies,upholstery, curtains, parachutes and tarps, etc.

SUMMARY

Hybrid yarns are formed by twisting together low denier ultra-highmolecular weight polyolefin fibers, which are preferably multifilamentpolyolefin fibers, with non-polyolefin fibers that are high quality,soft, and colored or colorable fibers. When each fiber type comprisesmultifilament fibers the fibers are twisted together such that thefilaments of each fiber are not mixed with each other, i.e., each of thefibers remain as discrete entities without blending or mixing of theircomponent filaments together. When fabricated into garments, theresulting products have desirable properties that satisfy a great needis the art. The polyolefin fibers enhance the strength and durability ofthe product, while the non-polyolefin fibers enhance the look and feel.Together, the yarn and fabric constructions achieve products havingoutstanding physical properties at a low weight, with low thickness andat a low cost that are attractive for use in a wide range of industries.

Particularly provided is a twisted yarn comprising a twisted combinationof one or more discrete polyolefin fibers and one or more discretenon-polyolefin fibers, wherein the twisted yarn has a yarn surface area,wherein said polyolefin fibers form greater than 20% of said yarnsurface area, and wherein said polyolefin fibers and said non-polyolefinfibers are twisted together. More particularly provided is a twisted,non-blended yarn comprising a twisted combination of one or morepolyolefin fibers and one or more non-polyolefin fibers, wherein thetwisted yarn has a yarn surface area, wherein said polyolefin fibersform greater than 20% of said yarn surface area, and wherein saidpolyolefin fibers and said non-polyolefin fibers are twisted together.

Also provided is a twisted yarn comprising a twisted combination of oneor more discrete polyolefin fibers and one or more discretenon-polyolefin fibers, each of said discrete non-polyolefin fibershaving a tenacity of 20 g/denier or less and each of said non-polyolefinfibers having a density of greater than 1.0 grams/cm³, and wherein saidfibers are twisted together. In the preferred embodiments the discretepolyolefin fibers comprise multifilament polyolefin fibers and thediscrete non-polyolefin fibers comprise multifilament fibers ormulti-staple spun yarn fibers (e.g., cotton yarns), and the componentfilaments/staples of each of the discrete fibers are preferably entirelynon-blended and non-intermingled with each other. More particularlyprovided is a twisted, non-blended yarn comprising a twisted combinationof one or more polyolefin fibers and one or more non-polyolefin fibers,said non-polyolefin fibers having a tenacity of 20 g/denier or less andsaid non-polyolefin fibers having a density of greater than 1.0grams/cm³, and wherein said fibers are twisted together.

Further provided is a process for producing a twisted yarn, comprising:a) providing one or more discrete polyolefin fibers; b) providing one ormore discrete non-polyolefin fibers, wherein said non-polyolefin fiberscomprise one or more elastic fibers, one or more natural fibers, or bothone or more elastic fibers and one or more natural fibers; c) layingsaid polyolefin fibers and said non-polyolefin fibers side-by-side inparallel to thereby form an untwisted fiber bundle of discrete fibers,wherein the untwisted fiber bundle has a surface area, and wherein saidpolyolefin fibers form greater than 20% of said fiber bundle surfacearea; and d) twisting said fiber bundle of discrete fibers to form atwisted yarn, wherein said polyolefin fibers and said non-polyolefinfibers are twisted together at a 1:1 ratio relative to each other,wherein the twisted yarn has a yarn surface area and wherein saidpolyolefin fibers form greater than 20% of said twisted yarn surfacearea. More particularly provided is a process for producing a twisted,non-blended yarn, comprising: a) providing one or more polyolefinfibers; b) providing one or more non-polyolefin fibers, wherein saidnon-polyolefin fibers comprise one or more synthetic fibers, one or morenatural fibers, or both one or more synthetic fibers and one or morenatural fibers; c) laying said polyolefin fibers and said non-polyolefinfibers side-by-side in parallel to thereby form a non-blended, untwistedfiber bundle wherein the untwisted fiber bundle has a surface area, andwherein said polyolefin fibers form greater than 20% of said fiberbundle surface area; and d) twisting said non-blended fiber bundle toform a twisted yarn, wherein said polyolefin fibers and saidnon-polyolefin fibers are twisted together at a 1:1 ratio relative toeach other, wherein the twisted yarn has a yarn surface area and whereinsaid polyolefin fibers form greater than 20% of said twisted yarnsurface area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a 2-ply, ply twisted hybridyarn.

FIG. 2 is a schematic representation of a 3-ply, ply twisted hybridyarn.

DETAILED DESCRIPTION

As used herein, a “hybrid” has the ordinary and customary meaning of athing made by combining two or more different elements, which in thecontext of the present disclosure are two or more different fiber types.As used herein, the term “yarn” is defined as a single continuous strandconsisting of multiple fibers, and a “hybrid yarn” combines together atleast two different discrete fibers (with a spun cotton yarn also beingreferred to as a fiber in this context). Also as used herein,“non-blended” means that the filaments of each fiber are not mixed witheach other and are not an “intimate blend” (a term that is understood bythose skilled in the art), wherein the component filaments of eachcomponent discrete fiber are preferably entirely not intermingled witheach other, i.e., preferably none of the individual filaments of onediscrete multifilament fiber/spun yarn are surrounded byfilaments/staples of another discrete multifilament fiber or evenpositioned between two filaments/staples of another discretemultifilament fiber (fully or partially). Rather, in the preferredembodiment, each fiber of the hybrid yarn remains entirely as a discretefiber before and after the fibers are twisted together, such asillustrated in FIGS. 1 and 2, with each filament/staple of eachrespective component discrete fiber remaining joined together with theother filaments of said respective discrete fibers. The hybrid yarns ofthis disclosure include at least two chemically different fiber types,at least one of which is a high tenacity, high tensile moduluspolyolefin fiber and at least one other being a non-polyolefin fiber. Asused herein, a “high tenacity, high tensile modulus” fiber is one whichhas a tenacity of at least 7 g/denier or more and a tensile modulus ofat least 150 g/denier or more, and preferably an energy-to-break of atleast about 8 J/g or more, each as measured by ASTM D2256 and alltensile strength properties (tenacity, tensile modulus andenergy-to-break) are measurements for dry fibers.

Provided that at least one polyolefin fiber and at least onenon-polyolefin fiber are incorporated, the hybrid yarns may also includemultiple different types of polyolefin fibers, for example differenttypes of polyethylene fiber having at least one dissimilar physicalproperty, and/or multiple different types of non-polyolefin fibers ofthe same chemical fiber type, for example, two different types ofpolyester fiber having at least one dissimilar physical property.

Examples of physical properties of fibers include fiber tensileproperties, such as tenacity, initial tensile modulus, ultimate tensilestrength and ultimate elongation/elongation-at-break. Other physicalproperties include fiber density, fiber denier, denier per filament,creep tendency (as determined by ASTM D6992), fiber diameter, electricproperties (including dielectric properties, such as dielectricconstant, and loss tangent properties), and thermal properties,including the coefficient of thermal expansion in fiber axial andtransverse directions.

For the purposes of the present disclosure, a “fiber” is an elongatebody the length dimension of which is much greater than the transversedimensions of width and thickness. The cross-sections of fibers for usein this disclosure may vary widely, and they may be circular, oblong oreven flat in cross-section. Thus the term “fiber” includes filaments,ribbons, strips and the like having regular or irregular cross-section.It is preferred that the fibers have a rounded or circularcross-section. A fiber is preferably a long, continuous strand ratherthan a short segment of a strand referred to in the art as a “staple” or“staple fiber.” A fiber may be a continuous filament fiber, i.e. acontinuous “strand,” or alternatively may be a short segment of a strandreferred to in the art as a “staple” or “staple fiber.” In this regard,a “strand” by its ordinary definition is a single, thin length ofsomething, such as a thread, fiber or wire. As is conventionally knownin the art, a plurality of staple fibers may also be combined to form acontinuous (long, non-filament) strand, such as by conventional spinningtechniques. Cotton yarns are spun yarns that are conventionally made inthis manner wherein each staple may have a length ranging from less thanone inch to about two inches or more, and for the purposes of thisdisclosure such spun cotton yarns are also referred to as“non-polyolefin fibers” herein.

A single fiber may be formed from just one filament or from multiplefilaments. A fiber formed from just one filament is referred to hereinas either a “single-filament” fiber or a “monofilament” fiber, and afiber formed from a plurality of filaments is referred to herein as a“multifilament” fiber. The definition of multifilament fibers hereinalso encompasses pseudo-monofilament fibers, which is a term of artdescribing multifilament fibers that are at least partially fusedtogether with heat and look like monofilament fibers. Multifilamentfibers of this disclosure preferably include from 2 to about 1000filaments, more preferably from 30 to 500 filaments, still morepreferably from 100 to 500 filaments, still more preferably from 100 to375 filaments still more preferably from about 100 filaments to about250 filaments and most preferably from about 120 to about 240 filaments.A multifilament fiber is also often referred to in the art as a“filament bundle.” A combination of a plurality of fibers (whethermonofilament fibers, multifilament fibers or a combination thereof) isreferred to herein as a “fiber bundle.” For example, when layingtogether polyolefin fibers and non-polyolefin fibers in side-by-side inparallel (though non-blended/unmixed and untwisted), the combination ofthe polyolefin and non-polyolefin fibers collectively is referred to asa “fiber bundle” wherein each of the polyolefin and non-polyolefinfibers individually is a “filament bundle” if they are multifilamentfibers.

The term “fabric” describes structures that may include one or morefiber plies, with or without attachment of or consolidation of theplies. For example, a woven fabric or felt may comprise a single fiberply or a plurality of plies of woven or felt fabrics may be sewn orstitched together. A non-woven fabric formed from unidirectionallyoriented fibers or non-parallel, randomly oriented fibers (e.g., a feltor mat) may comprise a single fiber ply or plurality of fiber pliesstacked on each other and laminated together (i.e., consolidated),typically with a binder being used to adhere the plies to each other, orthe plies may be sewn/stitched together. As described herein,“non-woven” fabrics include all fabric structures that are not formed byweaving. This includes knit fabrics formed from a single fiber ply or aplurality of fiber plies, forming loops or knit elements that areinterconnected with each other as is conventionally known in the art.

As used herein, the term “denier” refers to the unit of linear density,equal to the mass in grams per 9000 meters of fiber. As used herein, theterm “tenacity” refers to the tensile stress expressed as force (grams)per unit linear density (denier) of an unstressed specimen. The “tensilemodulus” of a fiber is the property of a material representative of itsresistance to deformation, referring to the ratio of the change intenacity, expressed in grams-force per denier (g/d) to the change instrain, expressed as a fraction of the original fiber length (in/in).

Particularly suitable high tenacity, high tensile modulus polyolefinfibers include high density and low density polyethylene. Particularlypreferred are extended chain polyolefin fibers, such as highly oriented,high molecular weight polyethylene fibers, particularly ultra-highmolecular weight polyethylene fibers, and polypropylene fibers,including ultra-high molecular weight polyethylene fibers, andparticularly including high toughness modulus (as determined by ASTMD2256-02) polypropylene fibers such as Innegra™ S fibers commerciallyavailable from Innegra Technologies LLC, of Greenville, S.C. In the caseof polyethylene, preferred fibers are extended chain polyethyleneshaving molecular weights of at least 300,000, preferably at least onemillion and more preferably between two million and five million. Suchextended chain polyethylene (ECPE) fibers may be grown in solutionspinning processes such as described in U.S. Pat. Nos. 4,137,394 or4,356,138, which are incorporated herein by reference, or may be spunfrom a solution to form a gel structure, such as described in U.S. Pat.Nos. 4,413,110; 4,536,536; 4,551,296; 4,663,101; 5,006,390; 5,032,338;5,578,374; 5,736,244; 5,741,451; 5,958,582; 5,972,498; 6,448,359;6,746,975; 6,969,553; 7,078,099; 7,344,668; 7,846,363; 8,361,366;8,444,898; 8,747,715 and 9,365,953, all of which are incorporated hereinby reference. Particularly preferred fiber types are any of thepolyethylene fibers sold under the trademark SPECTRA® from HoneywellInternational Inc. of Morris Plains, N.J. SPECTRA® fibers are well knownin the art.

Suitable non-polyolefin fiber types may be polymeric or non-polymericand may comprise synthetic fibers or natural fibers. Suitablenon-polymeric fibers include natural fibers such as cotton, cellulose,flax, ramie, hemp, sisal, silk and wool and may be in the form of acontinuous filament fiber, a staple fiber or a continuous strand madefrom a plurality of staple fibers. Suitable polymeric fibers may beelastomeric fibers or non-elastomeric fibers, and may be in the form ofa continuous filament fiber, a staple fiber or a continuous strand madefrom a plurality of staple fibers. Suitable non-polyolefin fibersinclude synthetic fibers formed from polyamides (nylons), aramid(meta-aramid and para-aramid), polyesters, polyvinyl alcohol,polyacrylonitrile, polyurethane, acrylics and acetate, and copolymersand blends thereof. Also useful are liquid crystal polymer fibers suchas VECTRAN™ fibers manufactured and commercially available from KurarayAmerica, Inc. of Houston, Tex., and non-synthetic renewable resourcepolymers, as well as combinations and copolymers of any of the abovefiber types. Suitable polyamide fibers non-exclusively include nylon 6fibers, nylon 66 fibers and nylon 4,6 fibers. Suitable polyester fibersnon-exclusively include polyethylene terephthalate (PET) fibers,polyethylene naphthalate (PEN) fibers, polybutylene terephthalate (PBT)fibers and polytrimethylene terephthalate (PTT) fibers. Suitablepolyurethane fibers are those known in the art as elastane fibers, whichare also known as spandex fibers, which are commercially available, forexample, from DuPont under the brand name LYCRA®. Also suitable arelastol fibers commercially available from Dow Chemical of Midland, Mich.Preferred aramid (aromatic polyamide) fibers are well known andcommercially available, and are described, for example, in U.S. Pat. No.3,671,542. For example, useful aramid filaments are producedcommercially by DuPont under the trademark of KEVLAR®. Also usefulherein are poly(m-phenylene isophthalamide) fibers produced commerciallyby DuPont of Wilmington, Del. under the trademark NOMEX® and fibersproduced commercially by Teijin Aramid Gmbh of Germany under thetrademark TWARON®; aramid fibers produced commercially by KolonIndustries, Inc. of Korea under the trademark HERACRON®; p-aramid fibersSVM™ and RUSAR™ which are produced commercially by Kamensk Volokno JSCof Russia and ARMOS™ p-aramid fibers produced commercially by JSC ChimVolokno of Russia. Preferred are para-aramid (p-aramid) fibers having atenacity of from about 22 g/denier to about 28 g/denier). Suitablenon-polyolefin fibers formed from renewable resource polymersnon-exclusively include poly-ϵ-caprolactone biodegradable fibers,poly-ß-propiolactone biodegradable fibers and polylactic acid-basedbiodegradable fibers. Also suitable are regenerated fibers such asviscose or rayon. Of all these fiber types, the most preferrednon-polyolefin fiber types are formed from cotton, silk, wool, polyesterand/or polyurethane fibers, particularly elastane fibers or other typesof elastic fibers.

Each of the polyolefin and non-polyolefin fibers may be of any suitabledenier. For example, fibers may have a denier of from about 20 to about3000 denier, more preferably from about 50 to 3000 denier, still morepreferably from about 200 to 3000 denier, still more preferably fromabout 650 to about 2000 denier, and most preferably from about 800 toabout 1500 denier. In the most preferred embodiments, all of theindividual fibers forming the hybrid yarns of this disclosure have adenier of greater than 100, preferably greater than 400, and still morepreferably from about 425 to about 800, although in some embodimentseach of the fiber types may have a denier of from about 50 to about 500,or about 50 to 400, or about 50 to 200, or about 50 to 150, or about 50to 100, or at least 50 to less than 100, or greater than 50 to less than100. As stated previously, continuous multifilament fibers of thisdisclosure preferably include from 2 to about 1000 filaments, morepreferably from 30 to 500 filaments, still more preferably from 100 to500 filaments, still more preferably from 100 to 375 filaments stillmore preferably from about 100 filaments to about 250 filaments and mostpreferably from about 120 to about 240 filaments. Each of the individualcomponent filaments forming these “filament bundles” have a denier perfilament (dpf) of at least 0.1, preferably from 0.1 up to about 7.0,more preferably from about 0.1 dpf up to about 6.0 dpf, more preferablyfrom about 1.0 dpf to about 6.0 dpf, more preferably from about 2.0 dpfto about 6.0 dpf, still more preferably from about 2.5 dpf to about 5.0dpf, and most preferably from about 3.0 dpf to about 5.0 dpf. It is notnecessary for the polyolefin and non-polyolefin fibers to have the samedenier or same dpf.

As stated above, the minimum tensile properties of the at least onepolyolefin fiber component of the hybrid yarn are a tenacity of at least7 g/denier, a tensile modulus of at least 150 g/denier, and preferablyan energy-to-break of at least about 8 J/g or more, each as measured byASTM D2256. Preferred fibers have a tenacity of about 10 g/denier ormore, more preferably about 15 g/denier or more, more preferably about20 g/denier or more, still more preferably about 25 g/denier or more,still more preferably about 30 g/denier or more, still more preferablyabout 35 g/denier or more, still more preferably about 40 g/denier ormore, still more preferably about 45 g/denier or more, and mostpreferably about 50 g/denier or more. Preferred fibers also have apreferred tensile modulus of about 300 g/denier or more, more preferablyabout 400 g/denier or more, more preferably about 500 g/denier or more,more preferably about 1,000 g/denier or more and most preferably about1,500 g/denier or more. Preferred fibers also have a preferredenergy-to-break of about 15 J/g or more, more preferably about 25 J/g ormore, more preferably about 30 J/g or more and most preferably have anenergy-to-break of about 40 J/g or more. Methods of forming each of thepreferred fiber types having these combined high strength properties areconventionally known in the art.

The tensile strength properties of the non-polyolefin fiber componentare not particularly important as it is not relied upon for its strengthproperties, but rather its light weight, dyeability and softness.Typically, the non-polyolefin fiber component will have a tenacity ofless than 10 g/denier, more typically less than 7 g/denier, still moretypically having a tenacity of 6 g/denier or less, or 5 g/denier orless, or 4 g/denier or less, and most typically having a tenacity of 3.0g/denier or less, or 2.5 g/denier or less, or 2.0 g/denier or less.Non-polyolefin fibers preferred herein also preferably have a tensilemodulus of less than 150 g/denier and an energy-to-break of less than 15J/g.

The non-polyolefin fiber type itself may alternatively comprise a hybridor a multi-component fiber, such as a core-sheath fiber, wherein eachcomponent is a non-polyolefin staple or continuous filament (mono ormultifilament) fiber. The non-polyolefin fiber type may also be awrapped fiber, as discussed in further detail below. Such fiber typesare known in the art. Additionally, more than one type of suchnon-polyolefin, multi-component fibers may be incorporated within thefabric constructions of this disclosure, as discussed in greater detailbelow.

The polyolefin and non-polyolefin fibers are joined together bywell-known plying or ply twisting techniques using conventional plytwisting equipment, such as a twister, wherein two or more single fibersare brought together and twisted together in the same twistingdirection. The single fibers may initially be laid together in parallelnext to each other or may be otherwise inserted together into a twistingapparatus set to impart the desired amount of twist. Suitable twistingapparatuses are commercially available from manufacturers such as SaurerTechnologies GmbH & Co. KG Twisting Solutions of Krefeld, Germany andMuratec Murata Machinery, Ltd. of Kyoto Prefecture, Japan. Aftertwisting, each of the individual fiber components of the ply-twistedyarn product is distinguishable from the others, i.e., one fiber is notentirely wrapped around another fiber of the multi-ply yarn no entirelycovers another fiber of the multi-ply yarn. The multi-ply yarns are notcore/sheath yarns.

The number of fibers that are twisted together determines the ply countof the yarn. As illustrated in FIG. 1, a 2-ply yarn 10 refers to a yarnformed by twisting together two discrete fibers (no blending/mixing ofthe filaments of one fiber with the filaments of another fiber of said2-ply hybrid yarn), identified as fibers 12 and 14 (wherein fibers 12and 14 may be selected from monofilament fibers, multifilament fibers,or fibers/yarns formed from a plurality of spun staple fibers, such ascotton yarns). As illustrated in FIG. 2, a 3-ply yarn 20 refers to ayarn formed by twisting together three discrete fibers (with noblending/mixing of the filaments of one fiber with the filaments ofanother fiber of said 3-ply hybrid yarn), identified as fibers 12, 14and 16 (wherein fibers 12, 14 and 16 may be monofilament fibers ormultifilament fibers, or fibers/yarns formed from a plurality of spunstaple fibers, such as cotton yarns). In the preferred embodiments, thehybrid yarns of this disclosure preferably comprise, consist of orconsist essentially of from 2 fibers to 12 fibers, preferably from 2 to10 fibers, more preferably from 2 to 8 fibers, and most preferably fromabout 2 to 6 fibers, wherein such yarns include at least two chemicallydifferent fiber types, with each fiber comprising one filament (i.e., amonofilament fiber) or a plurality of component filaments (i.e., amultifilament fiber; a filament bundle). However, hybrid yarns may befabricated from more than 12 discrete fibers, such as 3-20 or more, 3-30or more, 3-40 or more, 3-50 or more, or greater than 50 discrete fibers,such as 50-100 discrete fibers, depending on the end application.

In order to attain the preferred high abrasion resistance in a suitablebalance with other preferred properties such as soft feel, dyeabilityand low weight, it is necessary for the one or more polyolefin fibers toaccount for at least 20% of the surface area of the hybrid yarn up toabout 75% of the hybrid yarn, with the amount generally depending on theneeds of the end use application. In applications where abrasionresistance is more important than softness or dyeability, the yarnsshould include sufficient polyolefin fiber(s) so that they occupy agreater amount of the surface area of the hybrid yarn than thenon-polyolefin fiber(s). In this regard, in applications where softnessor dyeability is more important than abrasion resistance, the yarnsshould include sufficient non-polyolefin fiber(s) so that they occupy agreater amount of the surface area of the hybrid yarn than thepolyolefin fiber(s).

Accordingly, in one embodiment of the twisted, non-blended hybrid yarnsof this disclosure, the polyolefin fibers form less than or equal to 50%of the total surface area of the twisted, non-blended hybrid yarn. Inanother embodiment the polyolefin fibers form greater than or equal to50% of the total surface area of the twisted, non-blended hybrid yarn.In a particularly preferred embodiment, the polyolefin fibers form fromgreater than 66% of the total surface area of the twisted, non-blendedhybrid yarn up to 75% of the total surface area of the twisted,non-blended hybrid yarn. In another particularly preferred embodiment,the polyolefin fibers form from greater than 15% of the total surfacearea of the twisted, non-blended hybrid yarn up to 75% of the totalsurface area of the twisted, non-blended hybrid yarn, which is intendedherein to be inclusive of all ranges between these minimum and maximumvalues, including, for example, from 20% of the total surface area ofthe twisted, non-blended hybrid yarn up to 75% of the total surface areaof the twisted, non-blended hybrid yarn, more preferably from 20% of thetotal surface area of the twisted, non-blended hybrid yarn up to 70% ofthe total surface area of the twisted, non-blended hybrid yarn. In yetanother embodiment, the polyolefin fibers form from about 25% of thetotal surface area of the twisted, non-blended hybrid yarn up to about75% of the total surface area of the twisted, non-blended hybrid yarn.In yet another embodiment, the polyolefin fibers form from about 25% ofthe total surface area of the twisted, non-blended hybrid yarn up toabout 65% of the total surface area of the twisted, non-blended hybridyarn. In still another embodiment, the polyolefin fibers form from about25% of the total surface area of the twisted, non-blended hybrid yarn upto about 50% of the total surface area of the twisted, non-blendedhybrid yarn. In still another embodiment, the polyolefin fibers formfrom about 30% of the total surface area of the twisted, non-blendedhybrid yarn up to about 50% of the total surface area of the twisted,non-blended hybrid yarn.

As schematically represented in FIGS. 1 and 2, each of the illustratedfibers as shown has approximately equal size (denier), and thus eachfiber accounts for approximately one half (FIG. 1) or one third (FIG. 2)of the total surface area of the hybrid yarn. However, this will not bethe case for all embodiments because the denier of each component fibermay vary, and thus, their contribution to the surface area of the hybridyarn will correspondingly vary.

The extent of the total surface area occupied by a particular fiber typein the hybrid yarn (total surface area exposure) is determined by: (1)for each component fiber/yarn, first calculating the length offiber/yarn in cm for 1 gram of material using the known fiber/yarndenier; then, (2) from this, calculate the volume occupied by eachrespective yarn component using the known yarn/fiber density (e.g.,cotton density=1.54 cm³; SPECTRA® fiber density=0.97 cm³); then (3),since the volume of a cylinder (the fiber)=π×r²×h (=pi times radiussquared times height), the mass, density and length of the fiber areknown, r² can be calculated, and then r (cm), followed by using r tocalculate the surface area, which=(2×π×r²+2×π×r×h) cm² ((2 times pitimes radius squared) plus (2 times pi times radius times height),units=cm²). The surface area occupied by each yarn can be manipulated byincreasing the denier of the fiber types (greater denier willaccordingly correspond to greater surface area exposure, and lowerdenier will accordingly correspond to a lower surface area exposure).

In this regard, preferred polyolefin fibers are those having a preferreddensity of about 1.0 grams/cm³ or less, more preferably from 0.9grams/cm³ to about 1.0 g/cm³, and most preferably from about 0.93 g/cm³to about 0.97 g/cm³. Ultra-high molecular weight polyethylene, which isthe polymer of the most preferred polyolefin fiber types, has a densityof 0.97 cm³, though at very high molecular weights that may increase tofrom about 0.98 cm³ to about 0.995 cm³, as would be known by one skilledin the art. The preferred non-polyolefin fibers have a density ofgreater than 1.0 g/cm³, preferably from greater than 1.0 g/cm³ to about2.0 g/cm³, more preferably about 1.25 g/cm³ or greater, preferably from1.25 g/cm³ to about 2.0 g/cm³, still more preferably from 1.25 g/cm³ to1.60 g/cm³, still more preferably from 1.30 g/cm³ to 1.60 g/cm³ and mostpreferably from 1.30 g/cm³ to 1.55 g/cm³. In other embodiments, thenon-polyolefin fibers have a density of greater than 1.5 g/cm³, or from1.5 g/cm³ to about 2.0 g/cm³.

In a preferred embodiment, the hybrid yarn preferably, but notnecessarily, comprises a greater percentage by volume of said polyolefinfibers relative to said non-polyolefin fibers. In a preferredembodiment, the hybrid yarn has a polyolefin fiber content of from about20.0% by volume to about 70.0% by volume of the hybrid yarn with acorresponding non-polyolefin fiber content of from 30.0% by volume toabout 80.0% by volume, and inclusive of all ranges therebetween. Inanother preferred embodiment, the hybrid yarn has a polyolefin fibercontent of from about 33.3% by volume to about 66.7% by volume of theyarn with a corresponding non-polyolefin fiber content of from 66.7% byvolume to about 33.3% by volume. In another embodiment, the hybrid yarnhas a polyolefin fiber content of from about 40% by volume to about 60%by volume of the yarn with a corresponding non-polyolefin fiber contentof from 60% by volume to about 40% by volume. In another embodiment, thehybrid yarn has a polyolefin fiber content of from about 40% by volumeto about 70% by volume of the yarn with a corresponding non-polyolefinfiber content of from 60% by volume to about 30% by volume. In oneparticularly preferred embodiment, the hybrid yarns of the disclosureincorporate one type of polyolefin fiber (e.g., a single UHMW PE fiber)and two different non-polyolefin fiber components (e.g., one cottonfiber and one polyester fiber, or one cotton fiber and one elastanefiber). In this embodiment, the volume ratio of the first non-polyolefinfiber type relative to the second non-polyolefin fiber type may vary butis preferably from about 1:3 to about 3:1. Additionally, the hybrid yarnpreferably comprises a greater percentage by weight of said polyolefinfibers relative to the non-polyolefin fibers. In a preferred embodiment,the hybrid yarn has a polyolefin fiber content of from about 33.3% byweight to about 66.7% by weight of the yarn with a correspondingnon-polyolefin fiber content of from 66.7% by weight to about 33.3% byweight. In another embodiment, the hybrid yarn has a polyolefin fibercontent of from about 40% by weight to about 60% by weight of the yarnwith a corresponding non-polyolefin fiber content of from 60% by weightto about 40% by weight. In another embodiment, the hybrid yarn has apolyolefin fiber content of from about 40% by weight to about 70% byweight of the yarn with a corresponding non-polyolefin fiber content offrom 60% by weight to about 30% by weight.

Each of these fiber types may be individually twisted or untwistedbefore they are ply twisted together. Additionally, when multiplepolyolefin or non-polyolefin fibers are incorporated in the hybrid yarn,two or more of them may be twisted together (e.g., ply twisted) orentangled (if they are multifilament fibers; e.g., air entangled) priorto being ply twisted with the one or more polyolefin fibers. Variousmethods of twisting fibers are known in the art and any method may beutilized. Useful twisting methods are described, for example, in U.S.Pat. Nos. 2,961,010; 3,434,275; 4,123,893; 4,819,458 and 7,127,879, thedisclosures of which are incorporated herein by reference to the extentconsistent herewith. Similarly, various methods of air entanglingmultifilament fibers are conventionally known and described, forexample, in U.S. Pat. Nos. 3,983,609; 4,125,922; and 4,188,692, thedisclosures of which are incorporated by reference herein to the extentconsistent herewith. In a preferred embodiment, the individual componentfibers of the hybrid yarn are neither twisted nor air entangled prior toply twisting of the multiple fibers together to form a multi-ply hybridyarn.

The twister apparatus may be configured to impart any desired number oftwists to the combined yarn wherein the twist ratio of each fiber typerelative to each other fiber type is most preferably 1:1, i.e., the sameamount of twist is imparted to each fiber regardless of the number ofpolyolefin or non-polyolefin fiber types forming the twisted,non-blended hybrid yarn. However, the twist ratio of the one or morepolyolefin fibers to the one or more non-polyolefin fibers may vary, forexample, from about 10:1 to 1:10 inclusive of all ratios in between suchas from about 5:1 to about 1:5, or from about 4:1 to about 1:4, or fromabout 3:1 to about 1:3 or from about 2:1 to about 1:2. These twist ratioare irrespective of the number of polyolefin or non-polyolefin yarnsforming the twisted, non-blended yarn, and the preferred twist ratio mayvary depending on the intended end use application as would bedetermined by one skilled in the art.

Preferably, the fibers are twisted together a twist amount of from about0.5 twists per inch to about 20.0 twists per inch of the twisted yarn,more preferably from about 1.0 twists per inch to about 15.0 twists perinch, still more preferably from about 1.0 twists per inch to about 12.0twists per inch of the yarn, still more preferably from about 1.0 twistsper inch to about 10.0 twists per inch of the yarn, and most preferablyfrom about 1.0 twists per inch to about 8.0 twists per inch of the yarn,most preferably wherein the twist ratio of each fiber type relative toeach other fiber type is 1:1, i.e., the component yarns are broughttogether, without mixing or blending the filaments of the fiberstogether (i.e., they remain discrete and collectively the filamentsforming the hybrid yarn are “non-blended”), and they are twistedtogether with the same twist amount for the combined bundle ofyarns/fibers. The standard method for determining twist in twisted yarnsis ASTM D1423-02. Each of the individual fiber/yarn components of thehybrid yarn may similarly be twisted at or within the same twist amountranges.

Prior to twisting the polyolefin and non-polyolefin fibers together toform the hybrid yarn, each of the fiber components may individually becoated with a thermoplastic resin or polymeric binder material as wouldbe determined by one skilled in the art, such as a polymeric bindermaterial having adhesive properties. Alternatively, the hybrid yarnproduct comprising the twisted together fibers may be coated with athermoplastic resin or polymeric binder material for the same purposes.Suitable thermoplastic resins non-exclusively include polyolefin resinssuch as polyolefin wax, low density polyethylene, linear low densitypolyethylene, polyolefin copolymers, ethylene copolymers such asethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer,ethylene-vinyl acetate copolymer, polyisoprene-polystyrene-blockcopolymers (such as KRATON® D1107 commercially available from KratonPolymers of Houston, Tex.), polyurethanes, polyvinylidene fluoride,polychlorotetrafluoroethylene (PCTFE), and copolymers and blends of oneor more of the foregoing. Suitable polyolefin waxes non-exclusivelyinclude ACumist® micronized polyolefin waxes commercially available fromHoneywell International Inc. of Morris Plains, N.J. The most preferredthermoplastic resin will have a lower melting point than the individualfiber components of the hybrid yarn.

The fibers of the hybrid yarn may also be thermally bonded together orfused together with or without an adhesive coating. Thermal bonding andfusion are typically accomplished with the application of heat andtension, with the temperature conditions depending on the fiber typesand their melting or softening points. The fibers may also be at leastpartially pre-coated with an oil, solvent or plasticizing material priorto fusing or bonding, such as mineral oil, paraffin oil or vegetable oilas is conventionally known in the art, such as is described in U.S. Pat.Nos. 5,540,990; 5,749,214; and 6,148,597. As stated in said patents,mineral oil acts as a plasticizer that enhances the efficiency of thefusion/bonding process permitting the process to be performed at lowertemperatures. However, in the most preferred embodiments, the fibersforming the hybrid yarn are not fused together, i.e., they are unfused.It should also be understood that as used herein, the term “coated” isnot intended to limit the method by which the resin, polymeric binder,oil or other coating is applied onto the individual fiber or hybrid yarnsurfaces, and any conventional method may be used to coat the fibers,such as dipping, spraying or otherwise passing the fibers or hybrid yarnthrough bath of the coating material.

When the fibers of the hybrid yarn are coated with a thermoplastic resinor other polymeric binder material (either by coating the fibersindividually before ply twisting or as one after ply twisting), only asmall amount of the resin/binder is needed. In this regard, the quantityof resin/binder applied is typically no more than 5% by weight based onthe total weight of the fibers (individually or collectively) plus theweight of the coating, such that the fibers comprise at least 95% byweight based on the total weight of the fibers plus the weight of thecoating, and therefore the hybrid yarn will comprise at least 95% byweight of the component fibers. In more preferred embodiments, thehybrid yarn comprises at least about 96% fiber by weight, still morepreferably at least 97% fiber by weight, still more preferably at least98% fiber by weight, and still more preferably at least 99% fiber byweight. Most preferably, the hybrid yarns are completely resin andbinder free, i.e., they most preferably are not coated with any resin orpolymeric binder and consist essentially of or consist of onlyfibers/filaments.

After ply twisting, the hybrid yarn body itself may optionally be drawnto improve its properties, provided that the component fibers arecapable of being drawn. Drawing of the hybrid yarn is a separate processfrom drawing of the component fibers forming the hybrid yarn. In thisregard, polyolefin fibers are almost always drawn during theirfabrication prior to being ply twisted with other fibers in order toenhance their tenacity, as described in commonly owned U.S. Pat. Nos.7,846,363; 8,361,366; 8,444,898; 8,747,715 and 9,365,953. When it isdesired to draw the hybrid yarn with heat, but without fusing thecomponent fibers together, fusing is avoided by heating the hybrid yarnto a temperature below the melting point of the fibers. For example,when the hybrid yarn incorporates one or more ultra-high molecularweight, gel spun polyethylene multifilament fibers, the hybrid yarnstretching temperature is preferably within the range of from about 145°C. to about 153° C., more preferably from about 148° C. to about 151° C.

In this regard, it is noted that highly oriented, ultra-high molecularweight polyethylene fibers generally have a higher melting point thanbulk UHMW PE or lower molecular weight polyethylenes. During a drawingwithout fusion process, the hybrid yarn is preferably held under tensionthat is preferably applied continuously, and the stretching ispreferably conducted at an overall stretching ratio in one or morestages of stretching of from about 1.01 to about 3.0, and morepreferably from about 1.1 to about 1.8, with the application of heat.

The hybrid yarns of this disclosure may be produced into woven fabrics,knitted fabrics or non-woven fabrics. Non-woven fabrics include bothunidirectional non-woven fabrics, felts and non-woven mats.Alternatively the hybrid yarns may be formed into other non-fabricfibrous structures, such as ropes, including braided ropes as describedin U.S. Pat. No. 9,834,872 and U.S. pre-grant publications 2007/0202328and 2007/0202331, each of which is incorporated herein by reference tothe extent consistent herewith, or may be used as reinforcement threadsmaterials in articles such as fiber reinforced paper (e.g., kraft paper)and fiber reinforced tape (e.g., packaging or strapping tape) and thelike.

Methods of forming non-woven fabrics are well known in the art, such asby the methods described in U.S. Pat. No. 6,642,159, the disclosure ofwhich is incorporated herein by reference. For example, the yarns may beformed into one or more non-woven plies by arranging a plurality of thehybrid yarns in a unidirectional, substantially parallel array, with theply optionally being coated with a polymeric binder material to adherethe fibers together in the ply form. Suitable polymeric binder materialsare well known in the art and include both thermoplastic andthermosetting materials. A plurality of such plies may then be stackedand adjoined, such as by stitching or consolidation with heat andpressure by conventional lamination or molding techniques, or fabriclayers may just be glued together as is the case in a wet laminationprocess.

Woven fabrics may be formed using techniques that are well known in theart using any fabric weave, such as plain weave, crowfoot weave, basketweave, satin weave, twill weave and the like. Plain weave is mostcommon, where fibers are woven together in an orthogonal 0°/90°orientation. Also useful are 3D weaving methods wherein multi-ply wovenstructures are fabricated by weaving warp and weft threads bothhorizontally and vertically. Prior to weaving, the hybrid yarns orfibers forming the yarns may or may not be coated with a thermoplasticor thermosetting polymeric binder material.

Whether the fabrics are woven or non-woven, the polymeric bindermaterial may be a low modulus, thermoplastic material, a high modulus,rigid material or a combination thereof. Suitable low modulus polymericbinders include elastomeric materials having an initial tensile modulusless than about 6,000 psi (41.3 MPa), a preferred glass transitiontemperature (Tg) of less than about 0° C., more preferably the less thanabout −40° C., and most preferably less than about −50° C.; and apreferred elongation to break of at least about 50%, more preferably atleast about 100% and most preferably has an elongation to break of atleast about 300%. Suitable high modulus, rigid materials have an initialtensile modulus at least about 1×10⁶ psi (6895 MPa), each as measured at37° C. by ASTM D638. Examples of such materials are disclosed, forexample, in U.S. Pat. No. 6,642,159, the disclosure of which isexpressly incorporated herein by reference. As used herein throughout,the term tensile modulus means the modulus of elasticity as measured byASTM 2256 for a fiber and by ASTM D638 for a polymeric binder material.

The polymeric binder may be applied to a yarn of the disclosure in avariety of ways and as stated previously the term “coated” is notintended to limit the method by which the polymeric binder is appliedonto the fiber/yarn surfaces. When a binder is used, the binder quantityin the woven or non-woven fabrics will be from about 1% to about 50% ofthe total weight of the fabric, more preferably from about 1% to about25% of the total weight of the fabric and most preferably from about 1%to about 10% of the total weight of the fabric.

While the yarns of this disclosure are useful for generally any textileapplication, including wearable textile applications as well asnon-wearable textile applications, such as tents, canopies, upholstery,curtains, parachutes and tarps, they are particularly attractive in thefabrication of protective garments, including seamless garments, andmost particularly for the fabrication of high strength, abrasionresistant denim that is both functional and aesthetically attractivewhen used in garment applications.

Denim is a fabric that is traditionally made 100% from cotton yarns thatare woven in a twill weave, forming a pattern of diagonal, parallel ribsor ridges. As is conventionally known, the fibers in a twill weave maybe oriented in either in a left hand (LH or LHT (left hand twill)direction, being oriented diagonally upward to the left and downward tothe right, or in a right hand (RH or RHT (right hand twill)) direction,being oriented diagonally upward to the right and downward to the left).Denims are also typically characterized in the number of warp threads(yarns/fibers) relative to the number of weft threads (yarns/fibers) inthe weave. A 2×1 weave means that there are 2 warp threads in the weavefor every one weft thread. A 3×1 weave means that there are 3 warpthreads in the weave for every one weft thread, etc. The front facetends to have greater abrasion resistance than the rear because of thepresence of more warp fibers in the construction (2×1, 3×1, 4×1, etc.).

In accordance with the present disclosure, rather than a denim fabricbeing formed entirely from cotton fibers, an abrasion resistant denimfabric is formed where the twill woven fibers comprise, consist of orconsist essentially of the hybrid (twisted, non-blended) yarns of thisdisclosure wherein at least one polyolefin fiber is twisted togetherwith at least one cotton yarn. In the most preferred denim application,a twill woven, abrasion resistant denim fabric is fabricated whereineach of the yarns forming the denim fabric are hybrid yarns inaccordance with this disclosure wherein all of the hybrid yarnscomprise, consist of or consist essentially of three discrete fiberssuch as illustrated in FIG. 2, one of which is a polyolefin fiber, mostpreferably a continuous multifilament UHMWPE fiber, and the other twofibers being discrete cotton fibers, with each cotton yarn beingsubstantially similar to or identical to each other. In this example,the twill weave may be either LHT or RHT and may be any conventionaldenim weave style (2:1, 3:1, 4:1, etc.).

Additionally, it is conventional in a denim fabric that some of thecotton fibers will be dyed blue (e.g., with an indigo dye or bluereactive dye) while other cotton fibers are white (naturally white, dyedwhite or bleached). That is also preferred in the denim applications ofthe present disclosure, with any decorative pattern being acceptable asdesired by the manufacturer. Similarly, the polyolefin fiber componentof the twisted, non-blended hybrid yarns may be colored or non-colored.In one embodiment, the polyolefin is a black colored SPECTRA® fiber. Inanother embodiment, the polyolefin is a white SPECTRA® fiber. In anotherembodiment, the polyolefin fibers in some of the hybrid yarns are blackwhile others are white in the same fabric article, as would be readilydetermined by one skilled in the art. Each of the yarn types (with bluedyed cotton yarns; with white cotton yarns; with black polyethylenefibers; or with white polyethylene fibers, in any combination) may beused as either the warp threads or the weft threads as the manufacturerdesires.

In another desirable denim application, a twill woven fabric is formedwherein all the yarns forming the woven fabric are 3-ply hybrid yarns(again as illustrated in FIG. 2) as formed in accordance with thepresent disclosure, wherein the first discrete fiber of the yarn is apolyolefin fiber, most preferably a UHMWPE fiber; the second discretefiber of the yarn is a cotton fiber (any color, such as blue and/orwhite); and the third discrete fiber of the yarn is a polyurethane fibersuch as spandex (e.g., LYCRA™; also any color, e.g., black, white, blue,etc.) or another type of elastic/elastomeric fiber/yarn. In aparticularly preferred embodiment, each of the twisted, non-blendedhybrid yarns of this disclosure is a 3-ply (3-fiber/yarn) hybridincluding two cotton yarns and one UHMWPE fiber (e.g., SPECTRA®),wherein each cotton yarn has a preferred denier of from about 80 toabout 250, or from about 90 to about 225, preferably each having adenier of about 100, and wherein each UHMWPE fiber has a denier of fromabout 175 to about 425, more preferably from about 200 to about 400,with a most preferred hybrid yarn incorporating two cotton yarns eachhaving a denier of 100 or about 100 and one UHMWPE fiber having a denierof 400 or about 400, or incorporating two cotton yarns each having adenier of 100 or about 100 and one UHMWPE fiber having a denier of 200or about 200, incorporating two cotton yarns each having a denier of 221or about 221 and one UHMWPE fiber having a denier of 400, orincorporating two cotton yarns each having a denier of 221 or about 221and one UHMWPE fiber having a denier of 400 or about 400. Each fiber ineach of these exemplary embodiments may be dyed or colored usingconventional techniques in the art, including embodiments where theUHMWPE fiber is either a white SPECTRA® fiber or a black SPECTRA® fiber,and wherein the cotton fibers may be white or dyed blue.

In yet another embodiment, denim type fabrics may be fabricated from thetwisted, non-blended hybrid yarns of this disclosure wherein thenon-polyolefin fiber component of the hybrid yarn is a bi-component orwrapped fiber/yarn (e.g., helically wrapped core fiber/yarn), such as anelastomeric yarn (e.g., spandex fiber, such as LYCRA™) wrapped with acover of another fiber/yarn type such as one or more cotton yarns, oneor more nylon fibers, one or more polyester fibers, one or morepolyolefin (e.g., polyethylene, such as UHMWPE, or polypropylene),having any denier as would be determined by one skilled in the art,including fibers/yarns having deniers within the denier ranges asdescribed in this disclosure. For example, a denim fabric may be twillwoven in a 3×1 or 2×1 LHT or RHT construction with warp threads thatcomprise hybrid yarns of this disclosure comprising two blue cotton yarncomponents, each cotton yarn having an English Cotton Count (ECC) offrom about 12 to about 36, and one black or white SPECTRA®multi-filament fiber component having a denier of from about 200 to 600,preferably about 400, and with weft threads also comprising hybrid yarnsof this disclosure which comprise covered elastomeric yarn (e.g.,spandex fiber, such as LYCRA™) wrapped with cotton yarns or wrapped withnylon, polyester, UHMWPE or another polyolefin fiber of any selecteddenier. The wrapped yarn weft threads in this embodiment may alsocomprise more than one hybrid yarn type. For example, a first weft yarntype may comprise an elastomeric yarn wrapped with cotton yarn(s) and asecond weft yarn type may be an elastomeric yarn wrapped with nylonfiber(s). Any combination and/or variation of weft yarns can be used totailor the desired properties of the end fabric as determined by oneskilled in the art.

In this regard, the abrasion resistance, and thus wear performance, ofany fabric formed from the twisted, non-blended, hybrid yarns of thisdisclosure, including denim fabrics, may be tailored for either thefront face of the fabric or the rear (back) of the fabric by increasingthe surface area exposure of the polyolefin component (e.g., SPECTRA®fiber) of the hybrid yarn. This may be done by modifying the componentsused in the manufacturing of the hybrid yarn. For example, a hybrid yarnmay be formed from two or more polyolefin (e.g., SPECTRA®) fibers ratherthan one, in combination with one natural fiber yarn or onenon-polyolefin synthetic fiber/yarn. Or, the denier of the SPECTRA®fiber may be increased relative to the combined deniers or cotton counts(in ECC). In this regard, 24 ECC cotton yarn (approximately 221.5denier) is half the denier of a 12 ECC cotton yarn (approximately 443denier), and a 36 ECC cotton yarn (approximately 147.6 denier) is onethird the denier of a 12 ECC cotton yarn. Thus a single 400 denierSPECTRA® UHMWPE continuous filament fiber will have a greater surfacearea exposure than two 36 ECC cotton yarns, and thus the abrasionresistance will be greater for fabrics made entirely of this type ofyarn relative to a fabric formed exclusively from hybrid yarns formed byply twisting together two 24 ECC cotton yarns with one 400 denierSPECTRA® UHMWPE continuous filament fiber. The surface area exposure ofeach fiber type may also be manipulated by altering the twist amount ofeach individual fiber/yarn component of the hybrid yarn. In this regard,each individual polyolefin or non-polyolefin fiber/yarn may be twistedbefore the multiple yarns are ply twisted together. Twisting thepolyolefin fiber more will expose more of the polyolefin fiber at thesurface of the hybrid yarn product per unit area, and twisting less willreduce the amount of polyolefin fiber exposed at the surface of thehybrid yarn product per unit area, and the same is true for thenon-polyolefin yarn/fiber component.

While twill woven, denim applications including one or more cottonfibers is of particular interest herein, the hybrid yarns of thisdisclosure may be made into fabrics using any weaving, non-woven orknitting style, and twill woven fabrics may be fabricated without thehybrid yarns incorporating cotton fibers. For example, in anotherpreferred embodiment, the twisted, non-blended hybrid yarn may comprisea single UHMWPE fiber (e.g., SPECTRA®), one polyester fiber and onenylon fiber, with a particularly preferred example being a combinationof a 50 denier SPECTRA® fiber being combined with a 100 denier polyesterfiber and a 200 denier nylon fiber (˜12% SPECTRA® loading), but thesedeniers may vary as detailed above (e.g., 50-450 denier SPECTRA® fibercombined with a 50-250 denier polyester fiber and a 50-250 denier nylonfiber).

In addition, it is not necessary for fabric articles of this disclosureto be fabricated from only the hybrid yarns of this disclosure. Otherdiscrete fibers (monofilament or multifilament), hybrid yarns (e.g.,bi-component yarns or different hybrid yarns than taught herein) ornon-hybrid yarns (e.g., formed from multiple interconnected fibers suchas by twisting or entangling) may be incorporated.

In one alternative embodiment, a plurality of hybrid yarns of thisdisclosure may be woven together with a plurality of polyethylenefibers, such as SPECTRA® 900 UHMW PE fibers, SPECTRA® 1000 UHMW PEfibers or SPECTRA® 3000 UHMW PE fibers, all of which are commerciallyavailable from Honeywell International Inc. of Morristown, N.J. Inanother alternative embodiment, a plurality of hybrid yarns of thisdisclosure may be woven together with a plurality of one or morenon-polyolefin fiber types as described above.

In addition, fabrics formed solely or partially from the hybrid yarns ofthis disclosure may be combined with or attached to other fabrics thatare not formed either solely or partially from the hybrid yarns. In oneembodiment, a woven fabric formed by weaving the hybrid yarns of thisdisclosure together with said hybrid yarns forming both the warp yarnsand the weft/fill yarns may be combined (e.g., adhered, stitched to orsewn together) with a different woven fabric that incorporates nopolyolefin fibers, e.g., a fabric formed from cotton yarns, wool yarns,elastane yarns, or a combination thereof, as may be desirable forcertain end us applications. Fabrics formed from the hybrid yarns ofthis disclosure may also be used as protective patches or sections ofgarments, protective clothing or athletic wear, or non-wearable textilearticles, to enhance abrasion resistance in targeted sections of thearticles as would be determined by one skilled in the art.

Finally, due to the enhanced fabric strength imparted by the polyolefinfibers, highly abrasion resistant fabrics of this disclosure may be madethinner than comparative fabrics made from other materials such as 100%cotton fibers without sacrificing abrasion resistance performance. Inthis regard, the thickness of a single fabric layer produced from thehybrid yarns of this disclosure will generally depend on the denier ofthe hybrid yarns forming the fabric, so the thicknesses may vary. Inthis regard, a single layer of fabric may generally have a thickness offrom about 25 μm to about 600 μm per layer (i.e., per ply), or fromabout 50 μm to about 385 μm per layer/ply, or from about 75 μm to about255 μm per layer/ply, with the greater thicknesses generally beingachieved by increasing the denier of the yarns by increasing the numberof component fibers twisted together to form the hybrid yarns.Additionally, in order to further improve abrasion resistance, coatingsmay be applied to the face of the fabric, such as a coating ofpolyurethane or any other well-known abrasion resistant coating as isconventionally known in the art.

The following examples serve to illustrate the preferred embodiments.

EXAMPLE 1

A denim fabric of this disclosure was made by weaving together aplurality of twisted, non-blended composite yarns of the disclosure in atwill weave. Each twisted, non-blended composite yarn was made fromthree fiber/yarn types. The three fibers/yarns used to form eachcomposite yarn of the twill woven fabric were two cotton yarns and oneultra-high molecular weight polyethylene (UHMWPE) fiber. Cotton yarnsare spun yarns which are made by spinning together (or otherwisejoining) a plurality of cotton staple fibers into the form of a singleyarn, as is conventionally known in the art. Such cotton yarns arecommercially available in several varieties. The UHMWPE fiber used forall of these examples were 400 denier, continuous filament,multi-filament SPECTRA® S-1000 fibers having a tenacity of 36 g/denier,commercially available from Honeywell International Inc. However, anyfibers available the SPECTRA® trademark are useful herein as well asother polyolefin fiber brands, including other types of UHMWPE fibers.

To form the hybrid composite yarn, all three fibers/yarns forming thehybrid were first laid together in parallel with each other and thenthey were twisted together (at a 1:1 twist ratio relative to eachother). This resulted in the UHMWPE fiber being visible on the surfaceof the composite yarn, in a proportionate ratio among itself and thecotton yarns. In this example, the composite yarns used as warpdirection yarns incorporated two cotton yarns that were dyed deep blue(from indigo dyes) and have an English Cotton Count (ECC) of 24. TheSPECTRA® fiber was a 400 denier black (colored) fiber. The compositeyarns used as weft direction yarns incorporated two white 24 ECC cottonyarns (either dyed white and/or bleached white and/or naturally white(non-dyed)). The SPECTRA® fiber was a 400 denier white fiber.

In this example, a 3×1 LH (3-by-1 Left Hand) twill weave was used. The3-to-1 denotes that there are three warp yarns for each one weft yarn.Left Hand twill weave means that the warp threads are in a diagonalpattern that starts at the bottom right and moves up to the left of thefabric relative to the weft yarns that are used as interlacing. Thisweaving style was continued across the fabric giving a characteristicdenim feature of twill lines and exposing the highly abrasion resistantSPECTRA® fiber for the unique wear resistance feature of the denimfabric.

EXAMPLE 2

Similar to Example 1, another denim fabric was woven in a 3×1 LH twillweave construction with composite yarns having two cotton yarncomponents and one SPECTRA® fiber component. The composite yarn used inthe warp direction had two 24 ECC cotton yarns that were dyed deep bluewith a reactive blue dye and the SPECTRA® fiber was a black 400 denierfiber. The composite yarns used in the weft direction included two 24ECC white cotton yarns (dyed white and/or bleached and/or naturallywhite (undyed)) and the SPECTRA® fiber was a white 400 denier fiber. Ineach of Examples 1 and 2, the hybrid yarns had the following properties:

TABLE 1 Weight Ratio Denier Weight Type ECC (g/9000 m) Proportion Yarn 1Cotton 24 221 26% Yarn 2 Cotton 24 221 26% Yarn 3 UHMWPE N/A 400 47%

TABLE 2 Volume Ratio Density Volume Volume (g/cm³) Grams/Meter Grams/cm(cm³) Proportion Yarn 1 1.54 0.02460 0.00025 0.00016 21% Yarn 2 1.540.02460 0.00025 0.00016 21% Yarn 3 0.97 0.04444 0.00044 0.00046 59%

TABLE 3 Surface Area 1 Surface Surface Weight 1 Gram Meter Volume r AreaArea (g) Meters (m) (grams) (cm³) r² (radius) (3.14r²) % 221 9000 40.70.02456 0.01595 0.0051 0.07126 0.01595 21% 221 9000 40.7 0.02456 0.015950.0051 0.07126 0.01595 21% 400 9000 22.5 0.04444 0.04582 0.0146 0.120800.04582 59%

EXAMPLE 3

The front faces and rear surfaces of the twill woven fabrics of Examples1 and 2 were tested for abrasion resistance according to ASTM D4060using an H-18 testing wheel and a 1000-gram load weight. Compared to astandard cotton denim fabric fabricated with 100% cotton (all warp andweft threads being 24 ECC cotton yarns in a 3×1 LHT construction), theabrasion resistance of the denim fabrics formed from the hybrid(composite) yarns of this disclosure was substantially improved,increasing from 467 cycles to failure (standard cotton denim fabric) to6968 cycles to failure (denim fabric with all warp and weft threadsbeing the twisted, non-blended hybrid yarns as outlined in Tables 1-3)when comparing abrasion resistance at the front faces of each fabrictype, and from 407 cycles to failure (standard cotton denim fabric) to4879 cycles to failure (the same denim fabric with all warp and weftthreads being the twisted, non-blended hybrid yarns as outlined inTables 1-3) at the rear faces of each fabric type. That is animprovement in abrasion resistance performance of greater than 10× onboth the front face and rear surface of the fabric. The front face has agreater abrasion resistance than the rear because of the presence ofmore warp fibers in the 3×1 construction than weft fibers at the rearface.

EXAMPLE 4 (COMPARATIVE)

The abrasion resistance of a comparable DYNEEMA® denim fabric (fibersmanufactured by DSM Dyneema B.V. of The Netherlands) was testedaccording to the same conditions as in Example 3 (ASTM D4060; H-18testing wheel; 1000-gram load weight). The face of the fabric had afailure per unit weight of 467 cycles compared to 550 cycles (eachfabric being normalized to per unit weight of the fabric) with anincrease of 17% increase in abrasion performance on a per unit basis.

EXAMPLE 5 (COMPARATIVE)

Example 4 was repeated but the tested competitor's fabric was coatedwith a polyurethane coating to improve abrasion resistance. Theuncoated, twisted, non-blended hybrid yarn based fabric of thisdisclosure was still superior, with the competitor's fabric failing at537 cycles on a per unit basis compared to 550 cycles (again with eachfabric being normalized to per unit weight of the fabric) for thefabrics of Examples 1 and 2. The fabrics of this disclosure without asupplemental abrasion resistant coating was superior to the competitor'sproduct that included the additional coating that enhanced abrasionresistance.

EXAMPLE 6

Fabrics as per Examples 1 and 2 made with a 3×1 LH twill constructionfrom all hybrid composite yarn of SPECTRA® fiber twisted together withtwo cotton yarns were evaluated for weight loss after reaching theirfailure points during abrasion testing under the conditions of ASTMD4060 as per Example 3. The hybrid yarn-based fabrics had a lower weightloss than standard denim fabrics formed with 100% cotton yarns. Thefabrics of Examples 1 and 2 had a 34% lower loss of weight on the faceof the fabric and a 40% lower loss of weight on the back of the abrasiontesting machine.

EXAMPLE 7

Fabrics as per Examples 1 and 2 made with a 3×1 LH twill constructionfrom all hybrid composite yarn of SPECTRA® fiber twisted together withtwo cotton yarns were evaluated for tensile strength loss after reachingtheir failure points during abrasion testing under the conditions ofASTM D4060 as per Example 3. The fabric tensile strength per unit weightfor the fabrics of Examples 1 and 2 in both the warp and weft directionsof the fabric was compared to the standard 100% cotton fabric and toboth coated and uncoated DYNEEMA fabrics as described in Examples 4 and5. The fabric tensile strength of the hybrid yarn-based fabrics per unitweight was 1016% higher than standard 100% cotton denim, 31% higher thanuncoated DYNEEMA® fabric and 22% higher than coated DYNEEMA® fabric.

EXAMPLE 8

Similar to Example 1, another denim fabric was fabricated but with a 2×1LH twill weave with the warp hybrid composite yarns comprising two 24ECC indigo dyed blue cotton yarns twisted together with one 400 denierblack SPECTRA® fiber and the weft hybrid composite yarns comprising two24 ECC white cotton yarns twisted together with one 400 denier whiteSPECTRA® fiber.

EXAMPLE 9

Similar to Example 2, another denim fabric was fabricated but with a 2×1LH twill weave with the warp hybrid composite yarns comprising two 24ECC reactive blue dye dyed cotton yarns twisted together with one 400denier black SPECTRA® fiber and the weft hybrid composite yarnscomprising two 24 ECC white cotton yarns twisted together with one 400denier white SPECTRA® fiber.

EXAMPLE 10

Similar to Example 1, another denim fabric was fabricated but with a 4×1LH twill weave with the warp hybrid composite yarns comprising two 24ECC indigo dyed blue cotton yarns twisted together with one 400 denierblack SPECTRA® fiber and the weft hybrid composite yarns comprising two24 ECC white cotton yarns twisted together with one 400 denier whiteSPECTRA® fiber.

EXAMPLE 11

Similar to Example 2, another denim fabric was fabricated but with a 4×1LH twill weave with the warp hybrid composite yarns comprising two 24ECC reactive blue dye dyed cotton yarns twisted together with one 400denier black SPECTRA® fiber and the weft hybrid composite yarnscomprising two 24 ECC white cotton yarns twisted together with one 400denier white SPECTRA® fiber.

EXAMPLE 12

Similar to Example 1, another denim fabric was fabricated but with a 3×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC indigo dyed blue cotton yarns twisted together with one 400 denierblack SPECTRA® fiber and the weft hybrid composite yarns comprising two24 ECC white cotton yarns twisted together with one 400 denier whiteSPECTRA® fiber.

EXAMPLE 13

Similar to Example 2, another denim fabric was fabricated but with a 3×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC reactive blue dye dyed cotton yarns twisted together with one 400denier black SPECTRA® fiber and the weft hybrid composite yarnscomprising two 24 ECC white cotton yarns twisted together with one 400denier white SPECTRA® fiber.

EXAMPLE 14

Similar to Example 1, another denim fabric was fabricated but with a 2×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC indigo dyed blue cotton yarns twisted together with one 400 denierblack SPECTRA® fiber and the weft hybrid composite yarns comprising two24 ECC white cotton yarns twisted together with one 400 denier whiteSPECTRA® fiber.

EXAMPLE 15

Similar to Example 2, another denim fabric was fabricated but with a 3×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC reactive blue dye dyed cotton yarns twisted together with one 400denier black SPECTRA® fiber and the weft hybrid composite yarnscomprising two 24 ECC white cotton yarns twisted together with one 400denier white SPECTRA® fiber.

EXAMPLE 16

Similar to Example 1, another denim fabric was fabricated but with a 4×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC indigo dyed blue cotton yarns twisted together with one 400 denierblack SPECTRA® fiber and the weft hybrid composite yarns comprising two24 ECC white cotton yarns twisted together with one 400 denier whiteSPECTRA® fiber.

EXAMPLE 17

Similar to Example 2, another denim fabric was fabricated but with a 4×1RH twill weave with the warp hybrid composite yarns comprising two 24ECC reactive blue dye dyed cotton yarns twisted together with one 400denier black SPECTRA® fiber and the weft hybrid composite yarnscomprising two 24 ECC white cotton yarns twisted together with one 400denier white SPECTRA® fiber.

While the present disclosure has been particularly shown and describedwith reference to preferred embodiments, it will be readily appreciatedby those of ordinary skill in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe disclosure. It is intended that the claims be interpreted to coverthe disclosed embodiments, those alternatives which have been discussedabove and all equivalents thereto.

What is claimed is:
 1. A twisted, non-blended yarn comprising a twistedcombination of one or more polyolefin fibers and one or morenon-polyolefin fibers, wherein the twisted yarn has a yarn surface area,wherein said polyolefin fibers form greater than 20% of said yarnsurface area, and wherein said polyolefin fibers and said non-polyolefinfibers are twisted together.
 2. The twisted, non-blended yarn of claim 1wherein said polyolefin fibers are continuous ultra-high molecularweight polyethylene fibers and wherein said non-polyolefin fiberscomprise one or more synthetic fibers, one or more natural fibers orboth one or more synthetic fibers and one or more natural fibers.
 3. Thetwisted, non-blended yarn of claim 1 wherein said polyolefin fibers arecontinuous ultra-high molecular weight polyethylene fibers and whereinsaid non-polyolefin fibers comprise one or more elastic fibers, one ormore natural fibers or both one or more elastic fibers and one or morenatural fibers.
 4. The twisted, non-blended yarn of claim 1 wherein saidpolyolefin fibers are continuous ultra-high molecular weightpolyethylene fibers and wherein said non-polyolefin fibers comprise oneor more elastic fibers, one or more natural fibers and one or morenon-elastic synthetic fibers.
 5. The twisted, non-blended yarn of claim1 wherein said non-polyolefin fibers comprise both one or more cottonfibers and one or more elastic and/or non-elastic synthetic fibers. 6.The twisted, non-blended yarn of claim 1 wherein said non-polyolefinfibers comprise both cotton fibers and elastic fibers.
 7. The twisted,non-blended yarn of claim 1 wherein said non-polyolefin fibers compriseone or more elastic synthetic fibers, one or more non-elastic syntheticfibers, or both one or more elastic synthetic fibers and one or morenon-elastic synthetic fibers.
 8. The twisted, non-blended yarn of claim1 wherein said polyolefin fibers form from about 25% of the surface areaof the yarn up to about 65% of the surface area of the yarn.
 9. Thetwisted, non-blended yarn of claim 1 wherein said polyolefin fibers formfrom greater than 66% of the surface area of the yarn up to 75% of thesurface area of the yarn.
 10. The twisted, non-blended yarn of claim 1wherein said yarn comprises a first non-polyolefin fiber and a secondnon-polyolefin fiber, wherein said first non-polyolefin fiber and saidsecond non-polyolefin fiber are chemically different, and wherein thevolume ratio of the first non-polyolefin fiber type relative to thesecond non-polyolefin fiber type is from about 1:3 to about 3:1.
 11. Thetwisted, non-blended yarn of claim 10 wherein said first non-polyolefinfiber comprises one or more elastic fibers and said secondnon-polyolefin fiber comprises one or more natural fibers.
 12. Thetwisted, non-blended yarn of claim 10 wherein said first non-polyolefinfiber comprises one or more natural fibers and said secondnon-polyolefin fiber comprises one or more different natural fibers. 13.The twisted, non-blended yarn of claim 10 wherein said firstnon-polyolefin fiber comprises one or more nylon fibers and said secondnon-polyolefin fiber comprises one or more polyester fibers.
 14. Thetwisted, non-blended yarn of claim 1 wherein said twisted yarn comprisesa greater percentage by weight of said polyolefin fibers relative tosaid non-polyolefin fibers.
 15. The twisted, non-blended yarn of claim 1wherein the yarn has a polyolefin fiber content of from about 40% byvolume to about 70% by volume of the yarn.
 16. The twisted, non-blendedyarn of claim 1 wherein said twisted yarn comprises a greater percentageby volume of said polyolefin fibers relative to said non-polyolefinfibers.
 17. A woven, non-woven or knitted fibrous article formed from aplurality of twisted, non-blended yarns of claim
 1. 18. A twisted,non-blended yarn comprising a twisted combination of one or morepolyolefin fibers and one or more non-polyolefin fibers, saidnon-polyolefin fibers having a tenacity of 20 g/denier or less and saidnon-polyolefin fibers having a density of greater than 1.0 grams/cm³,and wherein said fibers are twisted together.
 19. The twisted,non-blended yarn of claim 18 wherein said twisted yarn has from about0.5 to about 15 twists per inch of length of the twisted yarn, whereinsaid polyolefin fibers are continuous ultra-high molecular weightpolyethylene fibers having a tenacity of greater than 20 g/denier,wherein said non-polyolefin fibers have a tenacity of at least about 10g/denier and wherein said non-polyolefin fibers have a density ofgreater than 1.5 grams/cm³.
 20. A process for producing a twisted,non-blended yarn, comprising: a) providing one or more polyolefinfibers; b) providing one or more non-polyolefin fibers, wherein saidnon-polyolefin fibers comprise one or more synthetic fibers, one or morenatural fibers, or both one or more synthetic fibers and one or morenatural fibers; c) laying said polyolefin fibers and said non-polyolefinfibers side-by-side in parallel to thereby form a non-blended, untwistedfiber bundle wherein the untwisted fiber bundle has a surface area, andwherein said polyolefin fibers form greater than 20% of said fiberbundle surface area; and d) twisting said non-blended fiber bundle toform a twisted yarn, wherein said polyolefin fibers and saidnon-polyolefin fibers are twisted together at a 1:1 ratio relative toeach other, wherein the twisted yarn has a yarn surface area and whereinsaid polyolefin fibers form greater than 20% of said twisted yarnsurface area.